After a 35% discount, a book costs $11.21, what is the normal undiscounted price of the book?
1 answer:
Answer:
The normal undiscounted price of the book is $17.25.
Step-by-step explanation:
This question can be solved using a rule of three.
After a 35% discount, a book costs $11.21
This means that $11.21 is 100-35 = 65% = 0.65 of the original price x.
How much is x, which is 100% = 1?
$11.21 - 0.65
$x - 1
The normal undiscounted price of the book is $17.25.
You might be interested in
Remark
The best way to answer something like this is to actually graph both equations. I have done that for you below.
Red Line: f(x) = 1/4x - 1
Blue Line: g(x) = 1/2x - 2
Now look at the answers.
A: The first one is incorrect. You don't need the graph to tell you that. The larger the number in front of the x, the steeper the line. Put another way, the larger the slope, the steeper the line. The y intercept is lower however.
B is wrong. g(x) is steeper, but the y intercept is lower not higher than f(x) [Negatives do strange things].
C:The g(x) is steeper (we've said that a couple of times), and it has a lower y intercept.
D is correct.
E is just wrong. Both parts are incorrect.
